diff --git a/Cargo.lock b/Cargo.lock
index 6daac2485e32a..9156bd97e661c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10763,6 +10763,15 @@ dependencies = [
  "futures-lite",
 ]
 
+[[package]]
+name = "smol_str"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4aaa7368fcf4852a4c2dd92df0cace6a71f2091ca0a23391ce7f3a31833f1523"
+dependencies = [
+ "serde_core",
+]
+
 [[package]]
 name = "smpl_jwt"
 version = "0.8.0"
@@ -13474,7 +13483,7 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 [[package]]
 name = "vrl"
 version = "0.33.1"
-source = "git+https://github.com/vectordotdev/vrl.git?branch=main#74e3e74582aa6b4445c1a94004bb3f14276d07df"
+source = "git+https://github.com/vectordotdev/vrl.git?branch=perf%2Fsmol-str-keystring#46f61ee8232d1ca9f8455788959f123e0c439b2b"
 dependencies = [
  "aes",
  "aes-siv",
@@ -13565,6 +13574,7 @@ dependencies = [
  "sha2 0.10.9",
  "sha3",
  "simdutf8",
+ "smol_str",
  "snafu 0.8.9",
  "snap",
  "strip-ansi-escapes",
diff --git a/Cargo.toml b/Cargo.toml
index 0fede344d2b1d..25d495f4b87aa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -224,7 +224,7 @@ vector-common-macros = { path = "lib/vector-common-macros" }
 vector-lib = { path = "lib/vector-lib", default-features = false, features = ["vrl"] }
 vector-vrl-category = { path = "lib/vector-vrl/category" }
 vector-vrl-functions = { path = "lib/vector-vrl/functions", default-features = false }
-vrl = { git = "https://github.com/vectordotdev/vrl.git", branch = "main", default-features = false, features = ["arbitrary", "cli", "test", "test_framework", "stdlib-base"] }
+vrl = { git = "https://github.com/vectordotdev/vrl.git", branch = "perf/smol-str-keystring", default-features = false, features = ["arbitrary", "cli", "test", "test_framework", "stdlib-base"] }
 mock_instant = { version = "0.6" }
 serial_test = { version = "3.4" }
 strum = { version = "0.28", features = ["derive"] }
diff --git a/LICENSE-3rdparty.csv b/LICENSE-3rdparty.csv
index 809e71411a172..a6fdf5f3b0966 100644
--- a/LICENSE-3rdparty.csv
+++ b/LICENSE-3rdparty.csv
@@ -729,6 +729,7 @@ sketches-ddsketch,https://github.com/mheffner/rust-sketches-ddsketch,Apache-2.0,
 slab,https://github.com/tokio-rs/slab,MIT,Carl Lerche <me@carllerche.com>
 smallvec,https://github.com/servo/rust-smallvec,MIT OR Apache-2.0,The Servo Project Developers
 smol,https://github.com/smol-rs/smol,Apache-2.0 OR MIT,Stjepan Glavina <stjepang@gmail.com>
+smol_str,https://github.com/rust-analyzer/smol_str,MIT OR Apache-2.0,Aleksey Kladov <aleksey.kladov@gmail.com>
 smpl_jwt,https://github.com/durch/rust-jwt,MIT,Drazen Urch <github@drazenur.ch>
 snafu,https://github.com/shepmaster/snafu,MIT OR Apache-2.0,Jake Goulding <jake.goulding@gmail.com>
 snafu-derive,https://github.com/shepmaster/snafu,MIT OR Apache-2.0,Jake Goulding <jake.goulding@gmail.com>
diff --git a/src/sources/fluent/message.rs b/src/sources/fluent/message.rs
index a096fabbd2c32..c8c16b481d3a4 100644
--- a/src/sources/fluent/message.rs
+++ b/src/sources/fluent/message.rs
@@ -54,7 +54,7 @@ pub(super) struct FluentMessageOptions {
 pub(super) struct FluentEntry(pub(super) FluentTimestamp, pub(super) FluentRecord);
 
 /// Fluent record is just key/value pairs.
-pub(super) type FluentRecord = BTreeMap<String, FluentValue>;
+pub(super) type FluentRecord = BTreeMap<KeyString, FluentValue>;
 
 /// Fluent message tag.
 pub(super) type FluentTag = String;